Jewel does not simulate complete heavy ion events, thermal background partons that do not participate in a scattering involving a hard parton never explicitly show up in the event. Instead, the event consists of partons coming from the hard matrix elements and the parton showers. It is possible to also keep the thermal partons that did interact with a hard parton (“recoils”) in the event, but then the thermal momentum these partons had before the interaction has to be subtracted from the final event. Two options for doing this, grid subtraction and four-momentum subtraction, are discussed in [1]}. Grid based subtraction has not been pursued further due to short-comings of the method. The four-momentum subtraction methods and its limitations will be briefly reviewed in the next section before a new method along the lines of constituent subtraction is introduced in section .
